Mixing of various materials, for example paint, has been the subject of numerous inventions. Early devices consisted of mechanical agitating machines capable of shaking a paint can or the like in order to mix the contents therein. These early devices required substantial mechanical structures and were often anchored to the floor since vibration was a major consideration. In order to improve upon these early devices, a subsequent generation of devices evolved that utilizes rotational motion about multiple axes to thoroughly mix the contents of a container with little or no vibration. U.S. Pat. Nos. 4,235,553 and 4,497,581 disclose two such rotational mixers. These types of rotational mixers are the preferred devices used today. Additionally, since these machines do not impart a vibrational or shaking motion to a can of paint, these devices do not require the operator to securely clamp the container of paint to be mixed into position.
While these devices are much quieter in operation than agititation devices, are more portable, are easier to use and are generally preferred, since no clamping of the paint can is required, these devices contain no means for securely holding the carrying handle, or bail in such a way as to prevent the unnecessary damage to the bail. Thus, a paint can carrying bail is capable to freely swinging during the mixing or blending operation of the machine, which could result in the carrying bail being deformed during the mixing or blending operation. Thus, it would be difficult to remove the paint can from the machine after the mixing or blending operation. Furthermore, if the carrying bail were to become dislodged during the mixing or blending operation, the carrying bail could become entangled in the motion generating mechanism of the machine and thereby cause severe damage the machine.
U.S. Pat. No. 4,445,782, which issued to Sparrow on May 1, 1984, discloses a paint can carrying bail retaining device used in a shaking-type paint mixing apparatus. While the device disclosed in the Sparrow reference accomplishes the same purpose as the invention of the Applicant claimed herein, there are fundamental distinctions between the devices. First, and perhaps foremost, in the Sparrow device, if a paint can is inserted into the paint shaking apparatus, the pain can carrying bail must be held in position by the operator with one hand while the operator displaces the bail retaining mechanism with his or her other hand. Thus, the securing of the paint can carrying bail in the Sparrow apparatus is a two-handed operation. Conversely, as will be more fully explained in below, the novel configuration of the Applicant's spring-compensated bail retaining device allows for the securing of a paint can carrying bail with a single hand.
The present invention overcomes the problem associated with prior art paint mixing machines by providing a device capable of securely holding a paint can carrying bail in a fixed position during the paint mixing or blending operation of a rotational paint mixing machine. The bail retaining device disclosed herein consists of a simple ring that is movably attached, and preferably pivotally attached, to a paint can blending bucket of a typical rotational material mixing machine and is sized specifically to allow a paint can carrying bail to be secured in position with a minimum amount of motion. This allows paint can carrying bails to be securely retained in position during the mixing or blending process and yet it also allows for simple and rapid insertion and removal of the paint can.